Dormitory Building Cake

I've been asked to create a cake that's a replica of the new dorm building at a university. It's an "L" shaped building in brick and the actual building is 5 stories tall. It has to feed about 200-225. I would love some opinion of how I'm going to construct this. My thought was using possibly a 9 x 13 for the long part of the "L" and then 9" squares for the short part. I was also going to use possibly a pound cake or sponge cake recipe - something pretty dense.

My initial measurements just playing with stacking pans last night was to have them 3 tiers high (each tier being 4"). The other thing is using plastic dowels rather than wood - it has to travel about 1 1/2 hours.

I thought I would do the fondant in panels possibly? Mixing red and brown fondant I can get a pretty good brick color and then use an impression mat for the look of brick.